IDLES LIKE CRAP IN ROCK

[theMucker]

I suspect that BMW went with the irregular idle in Rock because the majority associate it as a "hot rod" trait. I kinda like it. It's quite similar to the idle that my Stage 3 Roadmaster exhibits. I can understand why a rider might prefer a smooth idle. We're all individuals here.

 

[harleyel47]

What octane are you using?

 

[David R]

Tried all octane. 87, 89, 90 no ethanol, and 93 with etoh. Any BMW I had needs or likes 93.

I just need to accept it. Smooth as can be in ROLL or RAIN no matter what octane.
David

 

[Black Dog]

What octane are you using?

See page 67and 68 of the owners manual.

 

[David R]

I read the manual before I bought the bike and after a few times. I still tried all octane types.

87 it pings ONCE and the knock sensor figures out the new map.

Anything else, it runs fine.

David

 

[Tony the Skin]

95 and 99 Octane and mine is the same. There is a passing reference on page 80 of the R18C handbook to " in the Rock riding mode, the engine has a very spirited idle .... ". Seems to be the nature of the beast.

 

[Gilles]

I like so much this spirit !

 

[Pork Rind]

BMW and Bosch run a separate tune on Rock mode. The way they set up and map the engine mixture and ignition timing in Rock mode causes it to idle that way. Run it in Roll mode if it bothers you. Personally, I think it's stupid to design a tune that accentuates the lack of smoothness at idle, vibration destroys things, like adaptive headlights, shakes things unnecessarily.

Anyone that's owned an airplane knows how important it is to balance everything to make the whole engine and plane run smooth so as to not cause vibrations and metal fatigue and fasteners, bolts, nuts, and engine mount failures. The technology is there to design out vibrations. Harley Davidson counterbalanced the cranks on all Milwaukee 8 motors, starting in 2017. BMW should be capable of doing the same. I'm not fond of the engine being without a counter balanced crank, nor am I happy about the bike not being provided with hydraulic lifters. That's just plain cheap and dumb design. I'm not interested in 90 year old nolstagia. If I wanted that, I'd buy a Knuckle Head HD.

 

[R18-NIOC]

Something tells me that I will not be able to get this to idle smooth in ROCK.

It sounds terrible. Anyone tried to smooth it out?

I usually leave it in ROLL so when I stop, it does not shake and sputter while sitting at a light or when ever. Its smooth as can be. It should do that in ROCK too.

I am a life long mechanic. I remember folks telling me "its got a performance cam in it so this is the best it will Idle". Or "Its a performance engine" "Its supposed to sound like that".

Suggestions? Ideas?
David

I agree completely,
As an engineer I am mechanically sypethic to all my motorcycles.
Rock mode had a nice crisp throttle, like my Gixxer 1000 in A1. However the way my R18 shakes at traffic lights, gives me concerns for the steering head bearings.
Just a thought, If we had a User mode, say 1 to 5 Rock to Roll. What would you set yours to ? I would be set at 3, being Rock over 2k and roll when ticking over at junctions. It's only software, BMW, any chance ??

 

[estoma]

I agree completely,
As an engineer I am mechanically sypethic to all my motorcycles.
Rock mode had a nice crisp throttle, like my Gixxer 1000 in A1. However the way my R18 shakes at traffic lights, gives me concerns for the steering head bearings.
Just a thought, If we had a User mode, say 1 to 5 Rock to Roll. What would you set yours to ? I would be set at 3, being Rock over 2k and roll when ticking over at junctions. It's only software, BMW, any chance ??

R18-NIOC. David R, Pork Rind, and you are textbook Panic-Mechanics. So, you are worried that Rock Mode could make your Adaptive Headlight, Bolts & Nuts and Steering Head Bearings fail (?). WTF. I am also an engineer, and I have owned and wrenched motorcycles for 51 years. The R18 exhibits an annoying resonance higher up the rev range, but that has a mechanical origin, for which BMW has gone OTT on thread lock—another annoyance.

The R18 Rock Mode does not make the bike vibrate in the classic sense. And it only shakes (chops, lopes) while idling - engineered like that. It resembles, kind of, the classic Harley potato-potato lope of an Indian Thunderstroke motor with a Polaris Stage 2 cam and associated tune. Rock Mode adds a tad more go as well, especially with the BT Moto tune. So, soothe away peacefully in Roll Mode, or trade the R18 in on a Zero while the rest of us revel in Rock Mode (-:

BTW, the HD counterbalancer on the M8 motors has specifically been sized NOT to eradicate the V-twin trademark shake.

 

[Pork Rind]

BTW, the HD counterbalancer on the M8 motors has specifically been sized NOT to eradicate the V-twin trademark shake.

HD engineers, after much input from the public, decided to engineer in about 1/5th, or 20% of the vibration the M8 crank has over a Twin Cam. ie they got rid of 80% of the vibration with counterbalance on the crank. Even with 10.5 : 1 compression ratio on a 114 CI Low Rider S, the handlebars don't shake much with the stock cam. A stage 2 rpm cam, however, is another matter. A stage 2 torque cam with idle set slightly higher at 900 rpm ( to keep the battery charging ) is pretty damn smooth. Drop the rpm down to 800 or 850, and it starts sounding pretty lumpy and irregular.

I really, really do want a R18 B, but I'm hoping to see improvements when the next generation of them comes out, if ever.

 

[Noelpolar]

I am a fan of what this bike is..... so I want my shake..... but then I live in a town that doesn't have any traffic lights.... and then ride in lightly trafficked local hills.

And.... look forward to some quiet time with the bike to tinker with it's valve bits.... whilst also liking to live a bit dangerously.... so I'm trying to kick it's thread locker habit.... also no new crush washers or gaskets until it weeps.... some tuff love there.

 

[Rufus]

Might be missing something here but if you don’t like the idle/shake in Rock, isn’t that exactly what Roll mode is for? Just ride in Roll.

 

[Alan neill]

Something tells me that I will not be able to get this to idle smooth in ROCK.

It sounds terrible. Anyone tried to smooth it out?

I usually leave it in ROLL so when I stop, it does not shake and sputter while sitting at a light or when ever. Its smooth as can be. It should do that in ROCK too.

I am a life long mechanic. I remember folks telling me "its got a performance cam in it so this is the best it will Idle". Or "Its a performance engine" "Its supposed to sound like that".

Suggestions? Ideas?
David

I'm I life long mechanical as well I thought it was valve timing for optimum performance mine does the same but never stalls if you find out why it is please keep me in loop

 

[Pork Rind]

I'm I life long mechanical as well I thought it was valve timing for optimum performance mine does the same but never stalls if you find out why it is please keep me in loop

If you can change how it runs with the flick of the switch, from rain, roll, rock, that tells it's not mechanical, it's in the ECU tune, with 3 completely different tunes, as least at idle.

Valve timing is controlled by the grind of the cam, lift, duration, and timing overlap. They are all fixed at the time of the machining of the cam.